bonjour
7x + 2 = 2x + 3
7x - 2 x = +3 - 2
5x = 1
x = 1/5
3/x = 7/8
7*x= 3*8
7x = 24
x = 24/7
8(9-x) = 10x+4
72 - 8 x = 10x + 4
-8x - 10x = 4 - 72
-18x = -68
x = 68/18 = 34/9
(5x+6) (3x-9) = 0
soit 5x+6 = 0 => x = -6/5
soit 3x-9 = 0 => x = 3
(4x+1) (3x-7) = (6x+8) (2x-1)
12x² - 28x + 3x - 7 = 12x² - 6x + 16x - 8
-25x - 10x = -8 + 7
-35x = -1
x = 1/35
:)
